1. Field of the Invention
The present invention relates to fluid leakage sensing devices and, more particularly, to a conductive fluid leakage sensing device coupled to an electronic apparatus for indicating the initial occurrence of the conductive fluid leaking from a container.
2. Discussion of the Relevant Art
The prior art contains many liquid leakage systems that provide alarms when a leaking liquid is detected. Typical of these devices is that disclosed in U.S. Pat. No. 2,691,134 issued to C. J. Ford on Oct. 5, 1954, which requires a plurality of sensing devices disposed along the seams of a large reservoir, such as in an airplane gasoline tank. Should the leak occur at one of the seams, the sensor provides an indication that may be read on a meter.
U.S. Pat. No. 4,206,632 issued to Suzuki on Jun. 10, 1980 discloses a liquid leak detecting device that includes two electrical conductors arranged in parallel that is separated from each other by a material comprising a continuously porous polytetrafluoroethyleme (PTFE) that contains an electro-conductive material within its pores. The material disposed between the PTFE changes its resistance when contacted with a leaking liquid.
U.S. Pat. No. 5,203,202 issued to Spencer on Apr. 20, 1993 utilizes a layer of pliable conductive material between a conduit and signal carrying elements disposed along the length of the conduit. The conductive material is a layer of conductive tape wrapped around the conduit. Leakage of the gas from the pressured gas container causes a momentary ballooning of the conductive pliable layer, which upon contact with the exposed portion of the signal carrying elements alters the resistance between the conductors making up the signal carrying elements that is measured directly by the impedance changes.
The present invention overcomes the shortcomings of the prior art by providing a simple fluid leakage sensor and a sensing apparatus that utilizes the initial leakage of the conductive fluid to provide a pulse, which causes an indication on an output device.